Forbidden and Permitted Trapping on Shabbos (Part II)

  1. An insect on a person’s body that has stung him can be
    seized and removed. Because of the pain of the sting, the rabbis did not
    forbid this. Some are more lenient—and people who conduct themselves according
    to this leniency should not be rebuked—and permit the insect to be seized and
    removed even before it stings. If this can be done by flicking it off rather
    than taking hold of it, then it should be done that way. Nevertheless, it is
    forbidden to seize and remove an insect that is simply annoying and not
    causing physical pain. A noisy cricket, for example, or a buzzing fly may not
    be caught and tossed out.

  2. It is forbidden to spray insecticide if there is no way for
    the insects to avoid being killed. If the insects are not sprayed directly and
    a window or door is opened so that they can escape–some poskim permit it
    while others forbid it because it is hard to avoid spraying on the insects
    directly. (For the sake of a baby or a sick person, it is permitted.)

  3. Everyone agrees that it is permitted to use insect
    repellent, i.e., a liquid (not a cream, because it is forbidden to spread
    creams on Shabbos) that is spread on the body to repel insects.

  4. It is forbidden to toss insects (mosquitoes, etc.) into
    water because it kills them, and killing them on Shabbos is forbidden.

  5. It is permitted to flush the toilet even when there are
    insects in the toilet and flushing the toilet will almost certainly kill them.
    Not to flush is an offense to human dignity and in any case, the act of
    flushing is not a direct act of killing them: it is done for the sake of
    flushing the toilet, not killing insects.

  6. It is forbidden to kill hair lice on Shabbos. But it is
    permitted to check for lice and remove them without killing them. Doing so is
    not a violation of the prohibition of separating the desired from the
    undesired (borare). Nevertheless, a person should avoid removing the eggs that
    are stuck to the hair because he is liable to pull out the hair.